Interpretive Summary: Fruit rot caused by the fungal pathogen anthracnose, is the most important disease of blueberry and causes significant economic loss. We explored the possibility that volatile natural products that contribute to blueberry aroma and flavor also aid in resistance to fruit-rot after harvest and during storage. We compared volatile levels in non-inoculated and anthracnose fruit rot-inoculated blueberry fruit that were stored up to 5 days after harvest from 10 cultivars having a wide range of resistance to this disease. We found that aromatic volatiles in blueberry fruit are not inducible by anthracnose infection and volatile levels amongst cultivars are not correlated to disease resistance against Anthracnose Ripe Rot. This information will primarily benefit blueberry breeders and pathologists.

Technical Abstract:
Various volatile natural products are known to have antifungal activities. Blueberry fruit produce aromatic volatiles including trans-2-hexenal that may confer resistance to Anthracnose Ripe Rot, an important postharvest disease caused by Colletotrichum acutatum. To test the hypothesis that aromatic volatiles in blueberry fruit may be associated with postharvest disease resistance, we compared volatile concentrations in headspace extracts of C. acutatum-inoculated and non-inoculated blueberry fruit stored 0 to 5 days from 10 cultivars having a wide range of resistance to C. acutatum. While volatile concentrations including that of trans-2-hexenal varied amongst the cultivars with early ripening cultivars generally having higher volatile concentrations than later ripening cultivars, no consistent correlation was detected amongst cultivars with respect to anthracnose resistance. Aromatic volatiles decreased rapidly in most cultivars during storage, and exposure to anthracnose infection prior to storage had no effect on either volatile profiles or concentrations throughout storage. The results suggest that aromatic volatiles in blueberry fruit are not inducible by C. acutatum infection and do not contribute to disease resistance against Anthracnose Ripe Rot.